Google Wallet, originally announced in May 2011, is an application that transforms your phone into a virtual wallet. Citi, MasterCard, Sprint and First Data are working together to provide users with the ability to tap, pay, and save using their mobile device.

The first version of the app, which uses near field communication (NFC), was released to Sprint early last week. Sprint customers can look for the “Wallet” app and receive a $10 free Google Prepaid Card as a thank you for setting up an account before the end of the calendar year.

While Citi and MasterCard were launch partners with Google Wallet, the company remains true to their pledge of being an open commerce esystem. Since the launch, Visa, Discover, and American Express have made their NFC specs available so their cards can be added to future versions of the application.

What is the vision for Google Wallet? Google writes that their goal is to make it possible for members to add all payment cards to Google Wallet, eventually saying adieu to even the bulkiest traditional wallet.